This invention relates to combustion accelerators for use in elemental combustion analysis, the compositions thereof and to processes for their production.
Elemental combustion analysis is important in many major industries, including food, pharmaceuticals, chemicals, plastics, coal, coke, ceramics, steel, etc. The total quantity of an element or elements in a material is most often used to justify quality of a product. In many cases the element determination must be accurate and performed on a timely basis in order to allow production control to make appropriate adjustments in processing and allow for a timely product delivery.
In many combustion analyzers the sample material is combusted in an oxygen environment to release the various forms of elements as oxides. However, different types of elements with different strength of bonding may exist in a material, each of which may dissociate at a varying rate, creating a low analyzed result or a very long analysis time.
A typical example is sulfur in various organic and inorganic compounds. To avoid the problems of a low analyzed result or a very long analysis time, vanadium pentoxide (V.sub.2 O.sub.5) has traditionally been mixed with the sample to be analyzed, in order to accelerate sulfur release as SO.sub.2. However, recent concern over the toxicity of vanadium pentoxide has created a need for a new, non-toxic "accelerator" which can be used for elemental composition analysis.
In cases where objections to the use of vanadium oxide (V.sub.2 O.sub.5) exist, or no vanadium oxide (V.sub.2 O.sub.5) is available, high purity tungsten oxide (WO.sub.3) has been substituted for vanadium oxide (V.sub.2 O.sub.5) as a combustion aid. See LECO Corporation Application Bulletin, Form No. 203-601-229, August, 1992. Like vanadium oxide (V.sub.2 O.sub.5), tungsten oxide (WO.sub.3) is useful for its ability to assist in elemental oxidation during the combustion analysis process. However, the results obtained by using tungsten oxide (WO.sub.3) as the sole accelerator are not as beneficial as those obtained by vanadium oxide (V.sub.2 O.sub.5).